Magnesium 2-ethylhexanoate

Endpoint summary

Description of key information

In assessing the aquatic toxicity of magnesium 2-ethylhexanoate, read-across to the assessment entities soluble magnesium substances and 2-ethylhexanoic acid is applied since the ions of magnesium 2-ethylhexanoate determine its toxicity in the environment.

Magnesium as essential element for living organisms magnesium has a very low potential for toxicity to freshwater and saltwater organisms. However, experimental toxicity data are available for several species, although exceeding corresponding OECD test limits:

- an unbounded NOEC value of ≥ 500 mg/L magnesium was identified for microorganisms in activated sludge

- the lowest inhibitory concentration amounts to 121.3 mg/L magnesium for the green algal species Chlorella vulgaris

- a 48-h LC50 of 140 mg/L magnesium (Daphnia magna) represents the lowest value identified for freshwater invertebrates

- 96h-LC50 values ranging from 541 to 610 mg/L magnesium were determined for the toxicity of different magnesium sals and the freshwater fish Pimephales promelas.

- 48h-LC50 values of 4740 and 2800 mg/L magnesium were determined for saltwater fish species Cyprinodon variegatus and Menidia beryllina, respectively.

In sum, magnesium has a very low potential for acute aquatic toxicity.

2-ethylhexanoic acid

Acute data are available from studies for three trophic levels: algae, invertebrates and fish

- a 72-h ErC50 of 49.3 mg/L was identified for the algae Desmodesmus subspicatus (acc. To DIN 38412 part 9)

- a 48-h EC50 of 85.4 mg/L represents the lowest value identified for the invertebrate species Daphnia magna

- an unbounded value of > 100 mg/L (96-h LC50) was identified for the freshwater fish species Oryzias latipes based on data of an analogous substance (sodium 2-ethylhexanoate). Further studies of 2-ethylhexanoat with the freshwater fish species Oncorhynchus mykiss, Lepomis gibbosus and Leuciscus idus resulted in 96-h LC50 values > 100 mg/L

In sum, 2-ethylhexanoic acid has a low potential for acute aquatic toxicity.

Chronic data are available from studies for algae, aquatic invertebrates and microorganisms:

- a 72-h EC10 of 32.0 mg/L was identified for the green algae Desmodesmus subspicatus (acc. To DIN 38412 part 9)

- 21-d NOEC values of 18 mg/L and 25.0 mg/L were identified for Daphnia magna.

- a 17-h EC10 of 71.7 mg/L was identified for the inhibition of bacterial growth (Pseudomonas putida)

In sum, 2-ethylhexanoic acid has a very low potential for chronic aquatic toxicity to algae and invertebrates and appears to be of low toxicity to microorganisms.

Magnesium 2-ethylhexanoate

Using existing aquatic toxicity data of the dissociation products of magnesium 2-ethylhexanoate, the aquatic hazard assessment is based on the most toxic moiety.

Regarding acute (short-term) toxicity, magnesium has a very low potential. Existing aquatic toxicity data of 2-ethylhexanoate are recalculated for magnesium 2-ethylhexanoate based on a maximum 2-ethylhexanoate content of 92.18 %:

- a 72-h ErC50 of 53.5 mg/L was identified for the algae Desmodesmus subspicatus (acc. To DIN 38412 part 9)

- a 48-h EC50 of 92.6 mg/L represents the lowest value identified for the invertebrate species Daphnia magna

- an unbounded value of > 108.5 mg/L (96-h LC50) was identified for the freshwater fish species Oryzias latipes. Further studies with the freshwater fish species Oncorhynchus mykiss, Lepomis gibbosus and Leuciscus idus result in 96-h LC50 values > 108.5 mg/L

In sum, magnesium 2-ethylhexanoate has a low potential for acute aquatic toxicity.

Regarding chronic (long-term) toxicity, magnesium has very low potential. Existing aquatic toxicity data of 2-ethylhexanoate are recalculated for magnesium 2-ethylhexanoate based on a maximum 2-ethylhexanoate content of 92.18 %:

- a 72-h EC10 of 34.7 mg/L was identified for the green algae Desmodesmus subspicatus (acc. To DIN 38412 part 9)

- 21-d NOEC values 19.5 mg/L and 27.1 mg/L were identified for Daphnia magna.

- a 17-h EC10 of 77.8 mg/L was identified for inhibition of bacterial growth (Pseudomonas putida)

In sum, magnesium 2-ethylhexanoat has a very low potential for chronic aquatic toxicity to algae and invertebrates and appears to be of low toxicity to microorganisms.